1. Technical Field
The present disclosure relates to cathode active materials and methods for making the same and, particularly, to a cathode active materials for lithium batteries and methods for making the same.
2. Description of Related Art
Lithium ion batteries using a metal oxide such as LiCoO2 as a cathode active material and a carbonaceous material as an anode material, have high capacities and lifespan. Lithium ion batteries are widely used in portable electronic devices and in high power source markets such as for electric vehicles (EVs) and hybrid electric vehicles (HEVs). LiCoO2 is a commonly used cathode active material in commercial lithium ion batteries. However, LiCoO2 is relatively thermally unstable, toxic, and cobalt is limited.
LiNi0.5Mn0.5O2 is one of the most attractive alternative cathode active materials to the commercial LiCoO2, has been studied recently due to its higher specific capacity, lower cost, and excellent thermal stability. However, a poor rate capacity limits its applications. Yoshinari Makimura et al. studied the rate capability of the LiNi0.5Mn0.5O2 (Lithium Insertion Material of LiNi1/2Mn1/2O2 for Advanced Lithium-ion batteries, Journal of Power Sources 119-121 (2003) 156-160), and the result shows a notable capacity deterioration at a high rate (2 C), which hardly satisfies the actual application needs for a high rate discharge.
What is needed, therefore, is to provide a cathode active material with a good rate performance for lithium battery and a method for making the same.